This invention relates generally to the field of telecommunications and in particular to methods for assigning administrative weights pertaining to path selection in a communication network.
In many present networks, administrative weights are used as link weights in path-selection methods, for instance, in those methods using a shortest path algorithm, such as Dijkstra""s algorithm for route computation. Each link can have one administrative weight assigned for each possible class of service. The administrative weight of a path is the sum of the administrative weights of the component links. The administrative weight (hereinafter, AW) is typically a measure of the administrative policy or preference for usage of a link for the relevant class of service. Hence, links and paths with lower AWs are preferred by path selection methods over paths with higher AWs. Administrative weights thus enable a type of automatic path selection.
Nevertheless, assignment of administrative weights in the existing fashion based on some static assignment scheme can be overly pessimistic and result in unnecessary denials of service.
According to the present invention, administrative weights are assigned to links based on link call-blocking probabilities.
A first species of the invention employs switches of a uniform type and provides supplemental switch software to enable the switches to determine call-blocking probability and therefrom assign administrative weights for their links.
A second species of the invention employs an administrative weight network management station that monitors call-level statistics and obtains therefrom call-blocking probabilities. It determines the administrative weight values to be assigned to links to reflect call-blocking probabilities. Working with switches that satisfy certain standard conditions, the administrative weight network management station executes a network-wide optimization based on revenue optimization, which reflects traffic optimization. It determines AW values that tend to maximize total network throughput. The separate module for this species is called a Type I administrative weight network management station.
A third species of the invention employs an administrative weight network management station that monitors call-level statistics and derives call-blocking probabilities either for a switch or for a group of switches. It determines the administrative weight values to be assigned to links to reflect the call-blocking probabilities. Working with a wide variety of switches, it removes from the individual switches the burden of determining administrative weights of links. The separate module for this species is called a Type II administrative weight network management station.
Aspects of the invention lie both in the methods and the apparatuses for achieving these results.
Further features and advantages of the present invention, as well as the structure and operation of various species of the present invention, are described in detail below with reference to the accompanying drawing.